The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
North of 60 Mining News – September 21, 2018
Golden Predator is investigating the potential of using vat leaching to recover the gold at its Brewery Creek project east of Dawson City.
Golden Predator Mining Corp. Sept. 18 reported that its summer drill program at Brewery Creek has expanded gold mineralization around five zones at this producing gold mine about 55 kilometers (34 miles) east of Dawson City, Yukon.
This year's 22-hole drill program at Brewery Creek had two objectives – collect material for metallurgical testing to assess the viability of continuous vat leaching; and exploration drilling to extend known zones of gold mineralization through the targeting of high priority targets.
Brewery Creek hosts 14.2 million metric tons of indicated oxide resources averaging 1.27 grams per metric ton (577,000 ounces) gold and 9.3 million tons of inferred oxide resources averaging 0.93 g/t (279,000 oz) gold. In addition, the property hosts 3.5 million metric tons of indicated sulfide resources averaging 1.28 g/t (142,000 oz) gold and 12.4 million metric tons of inferred sulfide resources averaging 1.37 g/t (546,000 oz) gold.
This resource is found in 14 zones – nine previously mined and five undeveloped – plus material remaining on the heap leach pad from previous mining by Viceroy Resource Corp., which closed operations at Brewery Creek in 2002 due to the low gold prices at the time.
Golden Predator completed 800 meters of resource expansion drilling at Brewery Creek this year and reports that significant gold mineralization was encountered in eight of the nine exploration holes, extending five zones on the property – Lucky, Bohemian, Schooner, Sleeman, and Lone Star.
Two holes cut gold mineralization at Lucky zone, which hosts the easternmost historically mined pit at Brewery Creek.
Hole BC 18-604, drilled on the eastern margin of Lucky and 25 meters from the nearest hole, cut 8.5 meters of 5.05 g/t gold from a depth of 29 meters.
One hole drilled just southeast of Bohemian, which lies between Lucky and Schooner, cut eight meters of 1.72 g/t gold.
The one hole drilled at Schooner, BC 18-597, cut 6.55 meters of 3.03 g/t gold from a depth of 35.75 meters and 39.2 meters of 1.64 g/t gold from a depth of 52.9 meters in a sparsely drilled area outside of known mineralization.
Golden Predator drilled four holes at Sleeman, the easternmost zone identified so far at Brewery Creek, three of which cut gold mineralization.
Hole BC18-600 cut four zones of mineralization at Sleeman – three meters of 0.52 g/t gold from 28 meters; four meters of 0.41 g/t gold from 40 meters; two meters of 1.93 g/t gold from 58 meters; two meters of 0.45 g/t gold from 82 meters.
The company also drilled one resource hole at Lone Star, a zone south of the main east-west trend of mineralization at Brewery Creek. This hole, BC 18-605, cut six meters of 0.8 g/t gold from a depth of 50 meters and two meters of 21 g/t gold from a depth of 86 meters.
"We are very pleased with the success of the targeted exploration program which illustrates the untapped exploration potential of Brewery Creek," said Golden Predator Mining CEO Janet Lee-Sheriff. "To have hit mineralization away from known holes in a number of different zones and extend the Sleeman Zone for more than 200 meters along strike establishes a foundation that expands our exploration program to additional targets identified across this large claim block."
The company also completed 13 large diameter holes to collect material for metallurgical testing to assess alternate processing technology with the goal of enhancing the economics of the project.
A preliminary economic assessment completed for Brewery Creek in 2014 outlined plans for a heap-leach operation that would produce an estimated 372,000 oz of gold over a nine-year span. This includes mining 10.2 million metric tons of open-pit material from eight deposits averaging 1.35 g/t gold and reprocessing material located on the heap leach pad operated by Viceroy.
Under this scenario, mining and crushing would occur for 230 days per year.
The current metallurgical tests are assessing the viability of continuous vat leaching for both the oxide and sulfide resources evaluated in the 2014 PEA.
Continuous vat leaching utilizes large volume containers, described as vats, located in an enclosed temperature-controlled building, as opposed to heap leach technology, which involves stacking ore on pads in the open environment. The vat technology provides the opportunity to recover gold from some sulfide resources not amenable to heap leaching; greater saturation of the leaching solution; potentially improved recoveries of gold from the oxide resource; substantially shorter processing times; full year-round operations; and improved environmental considerations.
Golden Predator said the use of vat recovery at Brewery Creek indicates the potential for improved recoveries; bringing a larger portion of the resource base into the mine plan; improving environmental controls; and providing for more robust project economics.
Results from this metallurgical work are expected by the end of 2019.
–SHANE LASLEY
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